Grammarly vs ProWritingAid
Grammarly scores 8.3 to ProWritingAid's 3.9 among the AI writing assistants we rate, and is the better pick for 3 of the 4 kinds of buyer below.
Grammarly wins, 8.3 to 3.9
Grammarly writes new text from a prompt, detects AI-written text and rewrites AI text to read as human; ProWritingAid does none of those three. Both charge $30 a month for their cheapest paid plan, so the difference is what you get for it. ProWritingAid has no phone keyboard app and no team plan, where Grammarly covers both plus Slack, Outlook and Gmail add-ins. ProWritingAid says it does not train its AI on your writing; Grammarly lets individual users opt out but defaults training on.
Pick Grammarly if you want AI writing, detection and humanizing in one tool.
Pick ProWritingAid if you only need grammar and plagiarism checks, not AI generation.
Best for
Who each one suits, decided on the criteria that matter to that buyer and the checked facts where the two differ.
- Writes new text from a prompt: Grammarly yes, ProWritingAid no
- Writes in a saved voice or style: Grammarly yes, ProWritingAid no
- Builds citations: Grammarly yes, ProWritingAid no
- Your own style guide and terms: Grammarly yes, ProWritingAid no
- Team plan with shared settings: Grammarly yes, ProWritingAid no
- API: Grammarly yes, ProWritingAid no
- SOC 2: Grammarly yes, ProWritingAid no
- ISO 27001: Grammarly yes, ProWritingAid no
- But ProWritingAid leads on does not train AI on your writing: Yes against unless you opt out
How they score
Both are scored the same way, against the other AI writing assistants we rate, from facts on each vendor's own pages. Grammarly leads on 4 of 5 criteria.
Where they differ
Every point where the two vendors' published facts disagree, with a link to where each fact was read. "Not published" means the vendor does not say either way.
Where they match (4)
Pricing, plan by plan
Every plan each vendor publishes, monthly and yearly where both are offered.
Grammarly
ProWritingAid
Pros and cons
From each tool's full review, written from the same checked facts.
Grammarly
- Grammarly works across an impressive range of platforms including Chrome, Safari, Firefox, Edge, Windows, Mac, iOS, Android, Microsoft Word, and Google Docs.
- The plagiarism checker is built directly into the editor rather than being a separate export tool, a useful workflow for academic and content marketing use.
- Real-time grammar, spelling, and punctuation corrections remain reliable and are available even on the free plan.
- The Pro plan at $12/month billed annually unlocks full sentence rewrites, tone suggestions, and style clarity options at a competitive price point.
- Tone detection and brand voice features make it viable for enterprise teams managing content consistency across large organizations.
- Grammarly says it works across more than 500,000 apps and websites, making it one of the most broadly compatible writing tools.
- The free plan is significantly limited, though it does include tone detection and 100 AI prompts a month alongside basic grammar, spelling, and punctuation; most meaningful features still require a paid Pro subscription.
- Grammarly is now owned by Superhuman, which adds uncertainty about the product's long-term direction.
- Brand voice customization is heavily gated, with free users restricted to a single brand tone while unlimited options require an enterprise plan.
ProWritingAid
- Offers 25+ writing reports including pacing analysis, dialogue tag tracking, and repeated phrase detection that go far beyond surface-level grammar checks.
- Integrates with Scrivener, a major differentiator over Grammarly that fiction writers in long-form workflows genuinely value.
- Works across multiple environments including a web editor, desktop app, Chrome extension, Microsoft Word, and Google Docs.
- The Chapter Critique feature provides AI-driven feedback on entire chapters at once, approximating developmental editing rather than simple grammar correction.
- The Virtual Beta Reader simulates reader response feedback on manuscripts, offering fiction writers access to a resource they may not otherwise have.
- Sparks feature helps writers push through creative blocks by offering AI-powered inspiration and continuation mid-chapter.
- In development since 2012, giving it a long track record in writing software.
- Manuscript-level depth of analysis is available at a comparable price point to competitors that offer far less specialized feedback.
- Runs on a proprietary AI model with no recognizable third-party AI partnership, which may raise questions about model quality and transparency.
- The tool is heavily specialized for long-form fiction writers, making it potentially overkill or poorly suited for casual or business writers.
- The large number of reports (25+) can feel overwhelming and may require significant time investment to use effectively.
- Does not offer GPT-4 or similarly branded AI integrations that some competing tools use to establish credibility.
- Users coming from Grammarly may face a learning curve given the depth and complexity of ProWritingAid's feature set.
Grammarly vs ProWritingAid: common questions
Which is better, Grammarly or ProWritingAid?
Grammarly scores 8.3 and ProWritingAid 3.9 out of 10 among the AI writing assistants we rate. Grammarly is ahead on what it helps with, where it works, teams and control and privacy and security.
Is Grammarly or ProWritingAid cheaper?
Grammarly's cheapest paid plan is $12/mo (Pro plan, billed annually) and ProWritingAid's is $10.00/mo (Premium, billed yearly at $120/yr). Compare what each plan includes below before going on price alone.
What can Grammarly do that ProWritingAid cannot?
On the facts both vendors publish: writes new text from a prompt, writes in a saved voice or style, builds citations, detects AI-written text, rewrites AI text to read as human, phone keyboard that checks as you type, your own style guide and terms, team plan with shared settings, aPI, single sign-on, personal dictionary, sOC 2 and iSO 27001.
